Device for detecting the position of a gear step selector lever and motor vehicle equipped with same

ABSTRACT

A device for detecting the position of a gear step selector lever ( 2 ′) for selecting a gear setting of a motor vehicle has a signal transmitter ( 14 ) arranged at the gear step selector lever ( 2 ′) and a signal receiver ( 16 ) arranged spaced apart from the signal transmitter ( 14 ). The relative position between signal transmitter ( 14 ) and signal receiver ( 16 ) varies for different gear steps which can be selected. The signal transmitter ( 14 ) may be a magnet and the signal receiver ( 16 ) may be a triaxial Hall sensor system, designed so as to detect the relative position in three dimensions. Where the gear step selector lever ( 2 ′) has a ball joint ( 20 ), the signal transmitter ( 14 ) is arranged at one ball ( 22 ) of the ball joint ( 20 ). In this arrangement, a north-south-axis ( 18 ) of the magnet ( 14 ) does not run through a ball center ( 26 ). The invention further relates to a motor vehicle comprising a corresponding device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage application (under 35 U.S.C. §371)of PCT/EP2010/001964, filed Mar. 29, 2010, which claims benefit ofGerman application 10 2009 015 993.9, filed Apr. 1, 2009.

TECHNICAL FIELD AND STATE OF THE ART

The invention relates in a first aspect to a device to detect theposition of a gearshift lever for selecting a gear or the gear settingof a motor vehicle. The device has a signal transmitter installed on thegearshift lever and a signal receiver installed at a distance from thesignal transmitter, whereby the different position of the signaltransmitter relative to the signal receiver in different gears can bedetected. The invention also relates to a motor vehicle having such adevice.

Devices of the above-mentioned type are known in the state of the art.Automatic transmissions as well as the semiautomatic manualtransmissions of motor vehicles are typically actuated without a directmechanical coupling between the gearshift lever and the transmission. Inthese so-called “shift-by-wire” systems, the position of the gearshiftlever is detected and, on the basis of the actual position of thegearshift lever, the desired gear is ascertained, which is then set, forinstance, by means of auxiliary motors in the transmission.

Examples of commonly employed sensor means for such actuation devicesare light barriers that are associated with each shifting position ofthe gearshift lever in such a way that their beam paths are interruptedby the shifting lever itself or by the shadowing components that arecoupled to the movement of the shifting lever. Dirt on the light barriercomponents as well as wear of the mechanical components that couple themovement of the shifting lever to the shadowing components can impairthe function in such actuation devices and, in the worse-case scenario,cause complete loss of function.

Furthermore, systems consisting of signal transmitters and signalreceivers are known in which the signal transmitter is arranged on thegearshift lever and the signal receiver is arranged at a distance fromit, for example, in a gearshift lever housing.

A known device for this purpose is disclosed in German patentapplication DE 10 2004 056 800 A1 on a shifting device that has aholder, a gearshift lever pivotably mounted on the holder by means of ajoint as well as a signal transmitter and an angle-measuring deviceequipped with two sensors, whereby the angle-measuring device isarranged in the joint and electrically connected to a control unit thatis connected to a vehicle transmission.

A disadvantage here is that at least two sensors are required that arearranged at a distance from each other in order to detect the positionof the gearshift lever.

German patent application DE 102 2006 044 404 A1 discloses a device fordetecting the angular position of the gearshift lever in a motorvehicle, whereby two Hall sensors to detect the field direction of themagnetic field are likewise provided.

Moreover, German utility model DE 20 2007 000 210 U1 discloses anactuation device for a vehicle transmission, comprising a gearshiftlever that can be pivoted around at least one first pivoting axis intoat least two shifting positions and whereby at least one firstrotation-angle sensor is provided in order to determine the angularposition of the gearshift lever around the first pivoting axis. When itcomes to more complex two-dimensional movement possibilities of thegearshift lever, two sensors are also needed here so that the positionof the gearshift lever can be detected. Here, too, there is the drawbackthat, owing to the normally two-dimensional movements of the gearshiftlever in actual practice, at least two sensors are necessary. Therequisite wiring and computation resources are correspondingly higher inthese devices.

The device disclosed in German patent application DE 10 2007 026 303 A1for detecting and evaluating the gear selection in a motor vehiclehaving a gearshift lever, at least one magnet and at least one magnetsensor element that is suited to detect three spatial components of amagnetic field. The sensor can be configured as a Hall sensor.

SUMMARY OF THE INVENTION

Before this backdrop, an objective of the invention is to improve adevice of the above-mentioned type to the effect that the position of agearshift lever can be detected with a high degree of reliability and,at the same time, with little computation effort as well as with the useof a small amount of material.

A device according to the invention for detecting the position of agearshift lever for selecting the gear setting of a motor vehicle has asignal transmitter arranged on the gearshift lever as well as a signalreceiver arranged at a distance from the signal transmitter. Theposition of the signal transmitter relative to the signal receiver isdifferent in the various selectable gears and can be detected by thesignal transmitter and the signal receiver.

The term “gearshift lever” as set forth in the present invention shouldbe understood to refer to any device that can be manually actuated andwith which at least two different gears of the transmission of a motorvehicle can be selected. In this context, the type of transmission doesnot play a role for the invention. The transmission can be an automatictransmission or a semi-automatic transmission as well as a conventionalmanual transmission. A device according to the invention can serve, forexample, to display the gear.

It is provided according to the invention that the signal receiver isconfigured so as to detect the relative position of the signaltransmitter in three dimensions. Therefore, the invention makes itpossible to completely detect the position of a vehicle gearshift leverwith one single signal receiver. This eliminates the need for the use oftwo signal receivers and for the greater computation effort associatedwith it. The device according to the invention also facilitates theconstruction of a corresponding gearshift lever device since only onesignal receiver needs to be positioned and not more.

The relative position of the signal transmitter with respect to thesignal receiver in three dimensions can be ascertained in various ways.Thus, it is conceivable to record the three vector components betweenthe signal receiver and the signal transmitter. Moreover, it can also besufficient to detect two vector components as well as the value of thedistance vector. A third possibility to determine the three dimensionsconsists of determining three angles of a sensor signal that reaches thesignal receiver from the signal transmitter.

The evaluation of the signal and thus the determination of the positionof the signal transmitter relative to the signal receiver do not have becarried out directly in the signal receiver.

Furthermore, it is provided that the signal transmitter is configured asa magnet and the signal receiver is configured as a triaxial Hall sensorsystem. According to a refinement, the triaxial Hall sensor system canbe configured in such a way as to evaluate the direction and/or thevalue of magnetic field that is emitted by the magnet and that reachesthe triaxial Hall sensor system. The triaxial Hall sensor system ispreferably configured as a so-called 3D-Hall sensor.

As a rule, the evaluation of the direction vector of the magnetic fieldof the triaxial Hall sensor system will be sufficient since thegearshift lever is normally installed in a shifting gate and can thusassume defined positions that are characterized by a characteristicmagnetic field of the magnet in the triaxial Hall sensor system.

The energy supply for the signal receiver as well as the pick-up of thesignal are facilitated if the signal receiver is also arranged in afixed position in the vehicle. The signal receiver can be arranged, forexample, in a housing of the gearshift lever.

According to another refinement of the invention, the signal transmitteris arranged on a support frame. The support frame serves to support andguide the vehicle gearshift lever, for example, inside the shiftinggate. The gearshift lever is thus, for instance, cardanically suspendedlike a gimbal. Here, the arrangement of the signal transmitter on asupport frame means that the signal transmitter can be arranged in thevicinity of a suspension of the support frame, as a result of which thedistance between the signal transmitter and the signal receiver can besmaller and the signal receiver will require a lower level ofsensitivity. This increases the evaluation reliability.

An especially preferred arrangement of the signal transmitter is on afirst pivoting axis of the vehicle gearshift lever, and this is providedby the support frame. The arrangement of the signal transmitter on thepivoting axis allows the signal transmitter and the signal receiver tobe arranged especially close to each other.

The pivoting axis around which the gearshift lever can be pivotedrelative to the support frame is preferably used for this purpose. Inthis manner, when a gear is being selected, the signal transmitter isrotated and pivoted along relative to the housing around a secondpivoting axis around which the support frame itself is pivoted. Thus,when the vehicle gearshift lever is actuated, greater signal changes areachieved in the signal receiver than in the case of other arrangements.

As an alternative to this, it can be provided that the signaltransmitter is arranged on a side of the support frame that does not runthrough the second pivoting axis of the support frame described above,around which the support frame itself is pivoted relative to thevehicle. This, too, makes it possible to achieve large signal changeswhen different gears are selected.

If a magnet is employed as the signal transmitter in the above-mentionedsuspension of the gearshift lever in a support frame, the determinationof the position can be further improved in that the north-south axis ofthe magnet is oriented essentially perpendicular to the first pivotingaxis. Then, pivoting of the gearshift lever causes a pivoting of thenorth-south axis of the magnet relative to the signal transmitter andthus a very large change of the signal.

According to an embodiment of the invention, the vehicle gearshift leveris provided with a ball-and-socket joint guidance, whereby the signaltransmitter is then preferably arranged on the ball of theball-and-socket joint. When the vehicle gearshift lever is pivotedaround the ball-and-socket joint, the signal transmitter is pivotedtogether with the vehicle gearshift lever. The arrangement on the ballof the ball-and-socket joint allows a very uncomplicated arrangement ofthe signal receiver.

Another advantage can be obtained with a ball-and-socket joint guidanceif a north-south axis of the magnet does not run towards or through amid-point of the ball when a magnet is used as the signal transmitter.In this manner, a greater change of the magnetic field in the triaxialHall sensor can be achieved, thus improving the evaluation precision.

Another advantage is attained when the signal transmitter is arrangedinside a spherical surface formed by the radius of the ball of theball-and-socket joint. As a result, a better guidance of the gearshiftlever is achieved than with other arrangements of the signaltransmitter, for example, on the spherical surface of the ball of theball-and-socket joint or even outside of the spherical surface of theball-and-socket joint. This does not detrimentally affect the guidanceof the gearshift lever in a ball socket.

Preferably, the signal transmitter is arranged in the interior of theball. This can be achieved, for example, by means of an injection-moldedball into which the signal transmitter was inserted during the injectionmolding, or else by using a hollow or partially hollow ball in whoseinterior the signal transmitter is located.

As an alternative to this, it can be provided that the ball has aspherical section in which the signal transmitter is located.Consequently, the ball is not a complete ball, but rather has a recessin which the signal transmitter is arranged. The recess can be so largethat the signal transmitter complements the spherical surface or,alternatively, it can be cut open even further.

Preference is also given to an evaluation unit that is in communicationwith the signal transmitter in order to evaluate the signal of thesignal receiver. This facilitates the evaluation of the sensor signal.

A first independent subject matter of the invention relates to a vehiclehaving a device according to the invention described above.

Additional objectives, features and advantageous applicationpossibilities of the present invention ensue from the description belowof embodiments with reference to the drawings. In this context, all ofthe described and/or depicted features, either on their own or in anymeaningful combination, constitute the subject matter of the presentinvention, also irrespective of their compilation in the claims to whichthey refer back.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained on the basis of two embodiments. Thefollowing is schematically shown:

FIG. 1 a shifting lever with a device according to a first embodiment ofthe invention, in a perspective view;

FIG. 2 a sectional view of a section along the sectional line A-Athrough the device from FIG. 1;

FIG. 3 a vehicle gearshift lever with a device according to a secondembodiment of the invention, in a perspective view;

FIG. 4 a top view of the device from FIG. 3;

FIG. 5 a section through a vehicle gearshift lever according to thesecond embodiment, along the sectional line A-A in accordance with FIG.4; and

FIG. 6 a section through a vehicle gearshift lever according to thesecond embodiment of the invention, along the sectional line B-B fromFIG. 5.

DETAILED DESCRIPTION OF EMBODIMENTS

Two different embodiments of the invention will be described below. Forthe sake of clarity, components that are identical or that have the samefunction are designated by the same reference numerals in bothembodiments.

FIG. 1 shows a schematic three-dimensional view of a gear shiftingdevice having a device according to a first embodiment of the inventionfor detecting the position of a gearshift lever 2.

The gearshift lever 2 is installed in a shifting gate (not shown here)and it allows different gears to be selected, which are arranged in theshifting gate in two dimensions, for instance, in a conventionalH-arrangement of the various gears. The shifting gate can also provide,for example, for a sequential arrangement of the various gears and canhave a second gearshift or shift track.

The gearshift lever 2 is mounted so as to be pivotable in two directionsin a support frame 4. A first pivoting axis 6 is defined by a pivotingof the gearshift lever 2 relative to the support frame 4. A secondpivoting axis 10 is provided by mounting the support frame 4 by means ofbearing bolts 8 in a housing (not shown here) of the gearshiftarrangement.

In order to pivot the gearshift lever 2 around the first pivoting axis6, a pivoting shaft 12 that is rotatably mounted in the support frame 4is provided in the interior of the support frame 4. The pivoting shaft12 passes through the support frame 4 on the visible front of thesupport frame 4.

A magnet 14 is affixed onto one face of the bearing shaft 2. Oppositefrom the magnet 14, there is a Hall sensor 16 that allows athree-dimensional measurement of the magnetic field of the magnet 14.This is a 3D-Hall sensor.

A north-south axis 18 of the magnet 14 is oriented pair-wiseperpendicular to the pivoting axes 6, 10. A movement of the gearshiftlever 2 in order to select a driving gear requires a pivoting of thegearshift lever 2 around at least one of the two pivoting axes 6, 10.Due to the coupling between the magnet 14 and the pivoting axis 12, whenthe gearshift lever 2 is pivoted around the first pivoting axis 6, themagnet 14 is rotated relative to the Hall sensor. The magnetic fieldoriginating from the magnet 14 turns together with the magnet 14, andthe Hall sensor 16 registers this change in the magnetic field.

The measurement can be carried out statically or dynamically. A dynamicmeasurement, in other words, a measurement of the change in the magneticfield over the course of time, allows a causality examination and thusan improvement in the reliability of the position determination.

When the gearshift lever 2 pivots around the second pivoting axis 10,the distance between the magnet 14 and the Hall sensor 16 changes. Thishas an effect, on the one hand, on the absolute strength of the magneticfield of the magnet 14 in the area of the Hall sensor 16 and, to alesser extent, an influence on the direction vector of the magneticfield of the magnet 14 in the area of the Hall sensor 16.

In the case of more complex movements of the gearshift lever 2, thelatter pivots around the pivoting axis 6 as well as around the secondpivoting axis 10. As a result, the magnetic field of the magnet 14 isrotated relative to the Hall sensor 16 and thus weakened. The positionof the gearshift lever 2 can be clearly ascertained from the directionas well as of the strength of the magnetic field.

As an alternative to determining the strength of the magnetic field andof two components of the direction vector, it is also possible tomeasure all three components of the direction vector of the magneticfield of the magnet 14 in the area of the Hall sensor 16, therebydispensing with the need to measure the strength of the magnetic fieldof the magnet 14.

FIG. 2 shows a section through the arrangement according to FIG. 1,whereby the section is arranged perpendicular to the second pivotingaxis 10 at the height of the first pivoting axis 6. Pivoting thegearshift lever 2 around the second pivoting axis 10 causes the magnet14 to considerably increase its distance from the Hall sensor 16.

FIGS. 3 to 6 show a second embodiment of the invention. FIG. 3 shows aschematic perspective view of a gearshift arrangement comprising agearshift lever T that is guided by a ball-and-socket joint 20. Theball-and-socket joint 20 has a ball 22 that is pivotably mounted in aball socket (not shown here).

A magnet 14 is arranged in a ball recess 24, whereby a north-south axis18 of the magnet 14 is oriented in such a way that it does not runthrough a mid-point 26 of the ball 22. Adjacent to the magnet 14, thereis a Hall sensor 16 that is permanently installed in a housing of thegearshift arrangement, whereby the Hall sensor 16 is configured todetect the three-dimensional position of the magnet 14 relative to theHall sensor 16, as was the case with the previously describedembodiment. The above-mentioned techniques for measuring the relativeposition of the gearshift lever 2′ can also be employed in the secondembodiment.

Arranging the magnet 14 in such a way that its north-south axis 18 doesnot pass through the mid-point of the ball 22 makes it possible, forexample, as shown in FIG. 4, for the magnet 14 to run eccentrically withrespect to an axis 28 that runs through the mid-point of the ball 22,but with the north-south axis 18 parallel to the axis 28. In the secondembodiment, the axis 28 is positioned in such a way that it involves theshortest connection between the ball 22 and the Hall sensor 16.

The arrangement of the magnet 14 in the ball is illustrated in greaterdetail in FIGS. 5 and 6, each of which shows a section along thesectional lines A-A from FIG. 4 (FIG. 5) and B-B from FIG. 5 (FIG. 6).

The eccentric arrangement of the magnet 14 means that the magnet 14travels with a larger stroke when the gearshift lever 2′ is movedrelative to the Hall sensor 16. When the gearshift lever 2′ is moved ina first direction 30, the magnet 14 is moved on an orbit around the Hallsensor 16. A movement of the gearshift lever 2′ around a second pivotingdirection 32 leads to a change in the relative distance between themagnet 14 and the Hall sensor 16 as well as to a tilting of thenorth-south axis 18 of the magnet 14 relative to the Hall sensor 16.

The second embodiment also allows different ways of measuring therelative position between the magnet 14 and the Hall sensor 16 since thestrength of the magnetic field of the magnet 14 in the area of the Hallsensor 16 as well as the direction of the magnetic field vector of themagnetic field change during the pivoting.

While preferred embodiments of the invention have been described andillustrated here, various changes, substitutions and modifications tothe described embodiments will become apparent to those of ordinaryskill in the art without thereby departing from the scope and spirit ofthe invention.

LIST OF REFERENCE NUMERALS

-   2, 2′ gearshift lever-   4 support frame-   6 first pivoting axis-   8 support bolt-   10 second pivoting axis-   12 pivoting shaft-   14 signal transmitter, magnet-   16 Hall sensor-   18 north-south axis-   20 ball-and-socket joint-   22 ball-   24 ball recess-   26 mid-point of ball-   28 axis-   30 pivoting direction-   32 pivoting direction

The invention claimed is:
 1. A device to detect the position of agearshift lever (2, 2′) for selecting a gear setting of a motor vehiclein which the gearshift lever (2, 2′) has a ball-and-socket joint (20),in which a signal transmitter (14) comprises a magnet that is installedon the gearshift lever (2, 2′) by arrangement on or in a ball (22) ofthe ball-and-socket joint (20) with said magnet defining a north-southaxis (18) and a magnet mid-point, and a signal receiver (16) comprises atriaxial Hall sensor system that is installed at a distance from thesignal transmitter (14), and in which the position of the signaltransmitter (14) relative to the signal receiver (16) is different invarious selectable gear settings, characterized in that the north-southaxis (18) of the magnet (14) does not run through a mid-point (26) ofthe ball, and the magnet (14) is arranged eccentrically with respect toan axis (28) defined by a shortest distance between the ball (22) andthe Hall sensor (16) and running through the mid-point of the ball (22).2. The device according to claim 1, characterized in that the signalreceiver (16) is arranged in a fixed position in the motor vehicle. 3.The device according to claim 1, characterized in that the signaltransmitter (14) is arranged inside a spherical surface formed by theradius of the ball (22).
 4. The device according to claim 3,characterized in that the ball (22) has a section (24) in which thesignal transmitter (14) is located.
 5. The device according to claim 1,characterized in that the signal transmitter (14) is arranged in theinterior of the ball (22).
 6. The device according to claim 1, furthercomprising an evaluation unit (28) that is in communication with thesignal transmitter (14) in order to evaluate signal(s) of the signalreceiver (16).
 7. The device according to claim 1, characterized in thatthe north-south axis (18) is arranged parallel to the axis (28).
 8. Amotor vehicle, comprising: a device to detect the position of agearshift lever for selecting a gear setting of the motor vehicle inwhich the gearshift lever has a ball-and-socket joint, comprising asignal transmitter having a magnet that is installed on the gearshiftlever by arrangement on or in a ball of the ball-and-socket joint withsaid magnet defining a north-south axis and a magnet mid-point, and asignal receiver that comprises a triaxial Hall sensor system that isinstalled at a distance from the signal transmitter, and in which theposition of the signal transmitter relative to the signal receiver isdifferent in various selectable gear settings, wherein the north-southaxis of the magnet does not run through a mid-point of the ball, and themagnet is arranged eccentrically with respect to an axis defined by ashortest distance between the ball and the Hall sensor and runningthrough the mid-point of the ball.
 9. The motor vehicle of claim 8,wherein the signal receiver (16) is arranged in a fixed position in themotor vehicle.
 10. The motor vehicle of claim 8, further comprising anevaluation unit (28) that is in communication with the signaltransmitter (14) in order to evaluate signal(s) of the signal receiver(16).
 11. The motor vehicle of claim 8, wherein the north-south axisthat does not run through the mid-point of said ball is arrangedparallel to the axis running through the mid-point of said ball.
 12. Adevice to detect the position of a gearshift lever for selecting a gearsetting of a motor vehicle, comprising: a signal transmitter comprisinga magnet that is installed on or in a ball of a ball-and-socket jointforming the gearshift lever, said magnet defining a north-south axis anda magnet mid-point, and said ball defining a mid-point, a signalreceiver comprising a triaxial Hall sensor system that is installed at adistance from the signal transmitter, and in which the position of thesignal transmitter relative to the signal receiver is different in thevarious selectable gear settings, wherein the north-south axis of themagnet does not run through the mid-point of the ball, and the magnet isarranged eccentrically with respect to an axis defined by a shortestdistance between the ball and the Hall sensor and running through themid-point of the ball.
 13. The device of claim 12, wherein the magnet isarranged inside a spherical surface formed by the radius of the ball.14. The device of claim 12, wherein the north-south axis that does notrun through the mid-point of said ball is arranged parallel to the axisrunning through the mid-point of said ball.
 15. The device of claim 12,further comprising an evaluation unit that is in communication with thesignal transmitter in order to evaluate signal(s) of the signalreceiver.